Table using NSFetchedResultsController starts empty when using iCloud - objective-c

Question

I have my app set up to use core data with iCloud, but when it starts, the UITableView showing the data is empty, and takes a moment to fill with data. Is there any way to get it to display the data immediately, as if it didn't have iCloud integration?
- (NSManagedObjectContext *)managedObjectContext {
if (managedObjectContext != nil) {
return managedObjectContext;
}
NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
if (coordinator != nil) {
NSManagedObjectContext* moc = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType];
[moc performBlockAndWait:^{
[moc setPersistentStoreCoordinator: coordinator];
[[NSNotificationCenter defaultCenter]addObserver:self selector:#selector(mergeChangesFrom_iCloud:) name:NSPersistentStoreDidImportUbiquitousContentChangesNotification object:coordinator];
}];
managedObjectContext = moc;
managedObjectContext.mergePolicy = [[NSMergePolicy alloc]
initWithMergeType:NSMergeByPropertyObjectTrumpMergePolicyType];
}
return managedObjectContext;
}
- (void)mergeChangesFrom_iCloud:(NSNotification *)notification {
NSLog(#"Merging in changes from iCloud...");
NSManagedObjectContext* moc = [self managedObjectContext];
[moc performBlock:^{
[moc mergeChangesFromContextDidSaveNotification:notification];
NSNotification* refreshNotification = [NSNotification notificationWithName:#"SomethingChanged"
object:self
userInfo:[notification userInfo]];
[[NSNotificationCenter defaultCenter] postNotification:refreshNotification];
}];
}
- (NSManagedObjectModel *)managedObjectModel {
if (managedObjectModel != nil) {
return managedObjectModel;
}
NSString *modelPath = [[NSBundle mainBundle] pathForResource:#"EntryDatabase" ofType:#"momd"];
NSURL *modelURL = [NSURL fileURLWithPath:modelPath];
managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];
return managedObjectModel;
}
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator {
if((persistentStoreCoordinator != nil)) {
return persistentStoreCoordinator;
}
persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel: [self managedObjectModel]];
NSPersistentStoreCoordinator *psc = persistentStoreCoordinator;
// Set up iCloud in another thread:
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
// ** Note: if you adapt this code for your own use, you MUST change this variable:
NSString *iCloudEnabledAppID = #"IDRemovedFromStackOverflow";
// ** Note: if you adapt this code for your own use, you should change this variable:
NSString *dataFileName = #"CoreDataStore.sqlite";
// ** Note: For basic usage you shouldn't need to change anything else
NSString *iCloudDataDirectoryName = #"Data.nosync";
NSString *iCloudLogsDirectoryName = #"Logs";
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *storePath = [[self applicationDocumentsDirectory] stringByAppendingPathComponent:dataFileName];
NSURL *localStore = [NSURL fileURLWithPath:storePath];
NSURL *iCloud = [fileManager URLForUbiquityContainerIdentifier:nil];
if (iCloud) {
NSLog(#"iCloud is working");
NSURL *iCloudLogsPath = [NSURL fileURLWithPath:[[iCloud path] stringByAppendingPathComponent:iCloudLogsDirectoryName]];
NSLog(#"iCloudEnabledAppID = %#",iCloudEnabledAppID);
NSLog(#"dataFileName = %#", dataFileName);
NSLog(#"iCloudDataDirectoryName = %#", iCloudDataDirectoryName);
NSLog(#"iCloudLogsDirectoryName = %#", iCloudLogsDirectoryName);
NSLog(#"iCloud = %#", iCloud);
NSLog(#"iCloudLogsPath = %#", iCloudLogsPath);
if([fileManager fileExistsAtPath:[[iCloud path] stringByAppendingPathComponent:iCloudDataDirectoryName]] == NO) {
NSError *fileSystemError;
[fileManager createDirectoryAtPath:[[iCloud path] stringByAppendingPathComponent:iCloudDataDirectoryName]
withIntermediateDirectories:YES
attributes:nil
error:&fileSystemError];
if(fileSystemError != nil) {
NSLog(#"Error creating database directory %#", fileSystemError);
}
}
NSString *iCloudData = [[[iCloud path]
stringByAppendingPathComponent:iCloudDataDirectoryName]
stringByAppendingPathComponent:dataFileName];
NSLog(#"iCloudData = %#", iCloudData);
NSMutableDictionary *options = [NSMutableDictionary dictionary];
[options setObject:[NSNumber numberWithBool:YES] forKey:NSMigratePersistentStoresAutomaticallyOption];
[options setObject:[NSNumber numberWithBool:YES] forKey:NSInferMappingModelAutomaticallyOption];
[options setObject:iCloudEnabledAppID forKey:NSPersistentStoreUbiquitousContentNameKey];
[options setObject:iCloudLogsPath forKey:NSPersistentStoreUbiquitousContentURLKey];
[psc lock];
[psc addPersistentStoreWithType:NSSQLiteStoreType
configuration:nil
URL:[NSURL fileURLWithPath:iCloudData]
options:options
error:nil];
[psc unlock];
}
else {
NSLog(#"iCloud is NOT working - using a local store");
NSMutableDictionary *options = [NSMutableDictionary dictionary];
[options setObject:[NSNumber numberWithBool:YES] forKey:NSMigratePersistentStoresAutomaticallyOption];
[options setObject:[NSNumber numberWithBool:YES] forKey:NSInferMappingModelAutomaticallyOption];
[psc lock];
[psc addPersistentStoreWithType:NSSQLiteStoreType
configuration:nil
URL:localStore
options:options
error:nil];
[psc unlock];
}
dispatch_async(dispatch_get_main_queue(), ^{
[[NSNotificationCenter defaultCenter] postNotificationName:#"SomethingChanged" object:self userInfo:nil];
});
});
return persistentStoreCoordinator;
}
- (NSFetchedResultsController *)fetchedResultsController {
if (_fetchedResultsController != nil) {
return _fetchedResultsController;
}
//Set up the fetched results controller.
// Create the fetch request for the entity.
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Entry" inManagedObjectContext:[AppDelegate applicationDelegate].managedObjectContext];
[fetchRequest setEntity:entity];
// Set the batch size to a suitable number.
[fetchRequest setFetchBatchSize:20];
// Sort using the timeStamp property..
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"creationDate" ascending:NO];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[fetchRequest setSortDescriptors:sortDescriptors];
// Use the sectionIdentifier property to group into sections.
NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:[AppDelegate applicationDelegate].managedObjectContext sectionNameKeyPath:#"sectionIdentifier" cacheName:#"Root"];
aFetchedResultsController.delegate = self;
self.fetchedResultsController = aFetchedResultsController;
self.fetchedResultsController.delegate = self;
return _fetchedResultsController;
}

Answer 1

A possible solution would be to create a prepopulated .sqlite-file to your bundle, and copy it to the Documents directory just before creating the persistent store coordinator